math riddle ! 10 points!?

Hey

New member
Fed up with stair climbing, Joe Calculus decides there must be a better way to keep in shape. He
decides to start lifting weights, and orders some weights off the internet. Soon ten boxes arrive,
each containing 9 weights, but something is amiss! The weights in one box each weigh 0.9 lbs. The
rest all weigh 1 lb each. Joe may make just one weighing on an accurate scale. How will he find
the box containing the light weights?

please explain.
 
Back
Top